package com.xyhuo.leetcode.november;

/**
 * 不同路径Ⅱ
 * https://leetcode.cn/problems/unique-paths-ii
 *
 * @time 2023/11/23
 */
public class UniquePathsWithObstacles {

    public int uniquePathsWithObstacles(int[][] obstacleGrid) {
        if (obstacleGrid[0][0] == 1) {
            return 0;
        }
        int m = obstacleGrid.length;
        int n = obstacleGrid[0].length;
        int[][] dp = new int[m][n];
        dp[0][0] = 1;
        for (int i = 1; i < n; i++) {
            if (obstacleGrid[0][i] != 1 && dp[0][i - 1] != 0) {
                dp[0][i] = 1;
            }
        }
        for (int i = 1; i < m; i++) {
            if (obstacleGrid[i][0] != 1 && dp[i - 1][0] != 0) {
                dp[i][0] = 1;
            }
        }
        for (int i = 1; i < m; i++) {
            for (int j = 1; j < n; j++) {
                if (obstacleGrid[i][j] == 1) {
                    dp[i][j] = 0;
                } else {
                    dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
                }
            }
        }
        return dp[m - 1][n - 1];
    }
}
